Given an arbitrary graph G = (V, E) and an additional set of admissible edges F, the Chordal Sandwich problem asks whether there exists a chordal graph (V, E F ) such that F F. ...
The definitions of four previously studied parameters related to total coverings and total matchings of graphs can be restricted, thereby obtaining eight parameters related to cov...
Consider a tree T and a forest F. The paper discusses the following new problems: The Forest vertex-cover problem (FVC): cover the vertices of T by a minimum number of copies of tr...
It has been a challenging open problem whether there is a polynomial time approximation algorithm for the Vertex Cover problem whose approximation ratio is bounded by a constant l...